Home, office and other building-security systems are often used for safeguarding valuable possessions and for personal protection. These systems are typically implemented using different monitoring devices, such as cameras, motion sensors, keypads or contact sensors. Many buildings have multiple locations that are monitored for security purposes, requiring multiple monitoring devices in the different locations. For increased security and functionality, the monitoring devices can be configured to communicate with one or more central control devices. The central control device can, among other things, perform monitoring or recording functions, determine whether the building-security has been breached and whether to contact security personnel.
One method of communicating between the monitoring devices and the central control device is by a physical connection, such as electrical or other wiring. Using wiring to establish communication between the security devices can be troublesome for a number of reasons, such as the high cost of installation and maintenance. For example, exposed wiring is often unacceptable in a building, and thus, the installation of the security system requires passing the wires through the walls of the building. This type of installation can significantly increase the time required to complete a security system installation. Moreover, the troubleshooting and repair of the security system can be difficult because there is limited access to the unexposed wiring. The cost of the wire is another factor, especially in large buildings requiring numerous monitoring devices.
One potential solution is to use wireless monitoring devices to reduce or eliminate the need for physical connections between the devices, however, wireless security systems also have a set of problems, such as battery life. Ideally, the security devices would be self-powered by, for example, a battery. Self-powered devices are more secure because they are not subject to failure upon loss of power to the building. They also require less installation problems because they do not need to be connected to a separate power source; however, self-powered devices often have reliability issues due to the finite life of their power source. Increasing the useable time of a power source reduces the cost for replacement of the power source and increases the security of the entire system by having less potential downtime of the system or its components. Several recent developments have increased the potential power requirements of wireless security devices.
For example, the use of wireless communications in home, office and other buildings has been steadily increasing, creating additional issues with wireless security systems. One such issue is the increased potential for corrupted data due to interference between different wireless communications devices. This issue may also be present when an unauthorized person attempts to disrupt the security system by “jamming” the wireless communications using a wireless interference device. Techniques exist for reducing unwanted interference, however, the implementation of some of the techniques result in increased power requirements. Two such techniques, both of which can result in increased power requirements, include increasing the power of the transmission or varying the frequency of the transmission.
Another problem with power requirements arises from the desire to have increased monitoring capabilities with smaller devices. As security systems become more advanced, the power requirements of the monitoring devices are often increased. For instance, monitoring devices that contain digital cameras require enough power to run the camera, to store the digital picture in memory and to transmit the digital picture to the control device. The increased functionality of the monitoring devices, along with the desire to have smaller, less noticeable devices with less room for batteries or other power sources, has impacted the reliability of the monitoring devices.
Implementing a wireless building-security system can be further complicated by industry or government regulations. One such set of regulations is imposed by the Federal Communications Commission (FCC). The current regulations cover numerous aspects of wireless communications systems including, but not limited to, a range of restricted frequencies, a minimum number of different hopping frequencies within the allowable frequencies, the maximum output power of a transmitter and a requirement related to equal use of the hopping frequencies.
Attempts have been made to implement wireless security systems using a variety of methods. One such method is taught by European Patent Application Publication No. EP 1 363 260 filed on May 6, 2003, entitled “Procédé communication radiofréquence entre plusieurs dispositifs et système de surveillance mettant en œuvre un tel procédé,” which is fully incorporated herein by reference. Yet, these methods still leave room for improvement.
In order to protect residents, employees, personal property, and the like, security monitoring systems are used to monitor a variety of facilities and to sense the presence of unwanted intruders. Many such security systems are connected to a central control unit and monitored by an operator who can alert the appropriate emergency services in the event of an unwanted intruder. Typically, a home monitoring security system includes a combination of sensing devices and alarm devices and some also include cameras. To achieve the maximum monitoring coverage, these devices are distributed throughout the interior of the facility.
Security systems that employ cameras are advantageous in that they are able to record activity associated with a suspected breach of the facility and also can be used by a monitoring station to prevent false alarms. In some instances, however, the cameras record the regular activities of the facilities' residents and/or employees. The cameras also record activities that are falsely perceived to be security breaches such as pet behaviors and authorized users that have been accidentally locked out.
In specific situations, such as those having the potential to violate the privacy of authorized residents and/or employees of the facility, such comprehensive recordation by the security cameras may be undesirable. Since unwanted intruders could breach the security of a facility while the inhabitants are present, it is necessary for the security monitoring system to be functioning at all times. However, having cameras constantly being triggered to record the inhabitants' daily living and working routines is a dramatic invasion of the inhabitants' privacy, and is burdensome with respect to false triggers. Further, the monitoring and recording of guests' activities can be just as invasive.
Moreover, the installation and configuration of the various cameras and devices often requires complex and time-consuming installation procedures.
The above-discussed issues have presented challenges to developing a home and/or facility security monitoring system that provides maximum coverage while minimizing one or more of the above-identified issues.